Just because he is the CEO doesn’t mean he is directly liable. The company is a separate entity. I don’t see anyone arresting Elon or other CEOs because of “not enough moderation.” Most actions are to block platform access. There must be something else for sure.
Twitter doesn't encrypt messages, so there is indeed no chance of that happening - after all the reasoning for this arrest is fundamentally inapplicable to Twitter.
It's however a very very very slippery slope to prosecute someone for providing the tools to hold encrypted communication, just because this is also used by criminals. A lot of privacy oriented services would probably have to exit France if this holds up
by default telegram doesn't encrypt anything. I'm not sure if you where implying that telegram had encryption and therefore hiding illicite activities.
The problems is the huge telegram channels spreading hacks and illicite tricks.
I don’t know in France, but at least in Italy companies are not a shield for penal responsibility; crimes are always committed by persons. If a company does something criminal, someone is responsible for that decision within the company, and that could be the CEO.
Elon Mustk is a very important person; Tesla, SpaceX, Starlink, Twitter. He provides services to the military with the Starlink and he is deeply connected to the state with SpaceX.
On the other hand Pavel Durov is "homeless". He is like a normal citizen.
If a court orders twitter to take down a tweet, and twitter doesn't comply,
then I believe anybody that is responsible for that inaction, including Elon if he was aware and didn't act may be tried